Electrolytic process.



IINKTE STA orrion.

ELECTROLYTIC PROCESS.

To all whom it may concern:

Be it known that I, CHARLES J. REED, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inElectrolytic Processes, of which the follow ing is a specification.

My invention relates to an electrolytic process in which a gas,especially oxygen, is produced at one elect-rode, while a reversiblechemical action takes place at the other electrode without the evolutionof any gaseous product.

In the ordinary method of producing oxygen and hydrogen gases by theelectrolysis of an aqueous solution, electrodes are used which are inertand do not enter into the electrochemical reaction, hence chemicalchanges. occur in the electrolyte only. And it is customary to provideboth electrodes with hoods or receivers for collectin the two gases,which are produced in chemically equivalent quantities. It often occurs,how ever, that the oxygen only is required, the hydrogen being avalueless by-product.

According to my present process I produce a gas at one electrode only,and utilize the energy expended at the other electrode in producingvaluable non-gaseous products.

The following is a practical example of my process: Dilute sulfuric acidis electrolyzed with an anode of lead peroxid and a cathode of leadsulfate. Oxygen is evolved at the anode and'the lead sulfate of thecathode is simultaneously reduced to metallic lead without theevolutionof any gas. The reduced lead is a useful product, having a large amountof potential chemical energy, absorbed in reductlon and recoverable byresulfation. By replacing the lead sulfate cathode when reduced tometallic lead, the process may be made continuous. The metallic leadproduced by this electrolytic reduction of lead sulfate is usually in aspongy or minutely divided state, and is chemically very active. It maytherefore be utilized as a powerful reducing agent, either in an ordinary chemical reaction, or in an electrochemical reaction. For exampleit may be used as a purely chemical reagent for the reduction of ferricsulfate to ferrous sulfate, a reaction which rapidly takes place onmerely inserting the reduced spongy lead Specification of LettersPatent.

7 Application filed December 26, 1911.

Patented July 16, 1912.

Serial N 0. 667,607.

into a solution of ferric sulfate, and is rep- 5 resented by thechemical equation The sulfated lead electrode may now be used again as aregenerated cathode for producing an additional quantity of oxygen inthe electrochemical reaction. An electrochemical use for the spongyleadproduct is the electrolytic reduction in a separate receptacle ofmetals, such as metallic nickel, which cannot be reducedto a metallicstate by the spongy lead alone but Which may be reducedelectrolytically, using the spongy lead as an anode, with theexpenditure of a very small amount of electrical energy. To utilize thespongy lead in this manner, Iremove the cathode, which has been reducedfrom lead sulfate to spongy lead in producing oxygen gas, to a separatereceptacle containing a solution of a sulfate of a metal, such asnickel, and therein use it as an anode. The metallic nickel or othermetal is de posited on any suitable cathode, such as a rod or sheet ofmetallic nickel. In this reaction, the electrochemical change isrepresented by the chemical equation:

The spongy lead is reconverted into lead sulfate and the metallic nickelis deposited on the cathode. When the spongy lead has been sufiicientlyconverted into lead sulfate, it may againbe transferred to the originalreceptacle and used as a cathode 1n the generation of oxygen. Theoperation therefore 90 becomes cyclic, and the same electrode may beused alternately an indefinite numberof times, as cathode for theproduction of oxygen gas in the one receptacle and as anode for theelectrodeposition of a metal in the second receptacle.

The apparatus by which my process may be carried out isillustrated 1nthe accompanying drawing, in which- Figure 1 is a sectional view of anoxygengas generating cell; and Flg. 2 1s a slmilar view of a separatereceptacle for the electrodeposition of a metal.

Referring to Fig. 1: a receptacle 1 of suitable material contains anelectrolyte 2 of dilute sulfuric acid, in which is an .anodeconsistingof a sheet. of metallic lead 3 having a superficial coating oflead peroxid 4 Referring to Fig. 2: a sultable receptacle 12 contains asolution 13 of a metallic sul-- fate, such as nickel sulfate, in whichis placed the elctrode 8, reduced to spongy lead in the previousoperation and now act- I ing as anode. A cathode 14 of sheet nickel orother material is employed. The anode and cathode are connected to thesource of electrical energy 15 by conductors 16, 17. In practice, I havefound it desirable to wash out the electrolyte from the pores of theelectrode after removing it froin one receptacle and before inserting itin the other, to prevent contamination of the liquids. The reduction oflead sulfate to metallic lead in cell 1 causes a continuous addition ofsulfuric acid to the electrolyte 2, and increases its concentration. Itis therefore necessary to renew this electrolyte at suitable intervals,or remove a portion of it and replace it by water. The accumulatingsulfuric acid may be used as a by-product. By the operation going on inthe second receptacle 12, there is a withdrawal of both sulfuric acidand nickel from the nickel sulfate solution 13, which necessitates itsreplenishment with nickel sulfate or renewal with fresh solution fromtime to time.

I claim:

1. The process of electrolytically generating a gas, which consists inelectrolyzing a solution, using one electrode at which the desired gasis evolved and a second electrode which undergoes chemical reactionwithout gas-evolution, and removing and utilizing the second electrode.2. The process of electrolytically generatmg a gas, which consists inelectrolyzing a solution, using one electrode at which the desired gasis evolved and a second electrode which undergoes chemical reactionwithout gas-evolution, and removing and utilizing the second electrodeand restoring it to its original condition in a second receptacle.

3. The process of electrolytically generating a gas, which consists inelectrolyzing a solution, using one electrode at whichthe gas is evolvedand another electrode which undergoes chemical reaction withoutgasevolution, and restoring the chemicallychanged electrode to itsoriginal condition by a second electro-chemical reaction.

4. The process of electrolytically produca film of lead peroxid on itssurface and a cathode containing lead sulfate as chemically-activematerial, and removing the .cathode of metallic lead to a suitablereceptacle containing a nickel sulfate solution and thereinelectrochemically converting the metallic lead into lead sulfate.

6. The process of electrolytically generating a gas, which consists inelectrolyzing a solution, using one electrode at which the desired gasis evolved and another electrode which undergoes chemical reactionwithout evolving a gas, removing the chemicallychanged electrode,washing it free from solution, and restoring it to its originalcondition in a separate receptacle.

7 The process of electrolytically generating a gas, which consists inelectrolyzing a solution, using one electrode at which the desired gasis evolved and another electrode which undergoes chemical reactionwithout evolving a gas, removing the chemically- 'cha nged electrode,washing it free from so lutlon, and restoring it to its original COIl-'dition by a second electrochemical reaction.

8. The process of electrolytically producing oxygen gas, which consistsin electrolyzing a solution of sulfuric acid with an anode at whichoxygen is evolved and a cathode containing lead sulfate, removing thecathode of metallic lead, washin it'free from the solution, andelectrochemically converting it into lead sulfate in a separatereceptacle by an electrolyte'qontaining a metallic sulfate.

9. The process which consists in passing an electric current through asolution of sulfuric acid from an inert anode to a cathode of leadsulfate, and withdrawing the resulting oxygen and reduced lead.

10. The process which consists in passing an electric current through asolution of sulfuric acid from an inert anode to a cathode of leadsulfate, withdrawing the result ing oxygen and reduced lead, andelectrochemically converting the reduced lead back to lead sulfate.

11. The process which consists in passing an electric current through asolution of sulfuric acid from an anode of peroxidized lead to a cathodeof lead sulfate, withdrawing the resulting oxygen and reduced lead, andelectrochemically converting the reduced lead back to lead sulfate in asolution of nickel sulfate, with precipitation of the ing the reducedlead into lead sulfate in a nickel. solution of afmetallic sulfate. 1012. The process which consists in passing In testimony whereof I aifixmy signature an electric current through a solution of in presence oftwo witnesses.

sulfuric acid from an inert anode to a catch CHARLES J. REED. ode oflead sulfate, Withdrawing the result- Witnesses: s ing oxygen andreduced lead, Washing the FRANK A, ,LEACH,

reduced lead, and electrochemicallyconvert- J M. Jaoxsoiv.

